The most widespread medium for distributing motion pictures is the videocassette. The conventional practice is to provide only one language soundtrack on each videocassette. This means that different versions of the same motion picture must be prepared for distribution in different countries. Rather than to dedicate a different version of the same motion picture to each of several different languages, it would be far more advantageous to provide all desired sound tracks, containing different dialog languages, on the same carrier; this would require the production of far fewer versions of the same motion picture. Because of the large storage requirements, however, this has not proven to be practical. In fact, the only practical consumer use of multiple sound tracks on the same carrier is the provision of annotated and non-annotated soundtracks in some laserdisc releases. (It is possible, for example, to store different soundtracks in the digital and analog audio channels of a laserdisc.)
Despite the fact that it has occurred to others in the prior art to provide multiple soundtracks on the same software carrier, certainly the provision of perhaps a dozen different soundtracks, in different dialog languages, all on the same consumer software carrier, is not to be found anywhere. Not only are there no consumer players capable of selecting one from among so many different soundtracks, but software publishers have just not found it practical to store so much audio information on a single carrier. The traditional approach is to publish different versions of the same motion picture for distribution in different territories where different languages are spoken.
The idea of providing numerous different soundtracks, in different dialog languages, all on the same consumer software carrier, would not only be attractive to motion picture companies but could give rise to totally different applications of the same underlying technology. These applications would make use of audio tracks, representing audio signals, in ways which may be totally unrelated to the play of motion pictures. In fact, the present invention contemplates the storage of dozens of different audio signals on a software carrier which does not even contain visual information or conventional dialog soundtracks.
The storage is ditigal. A particular advantage of the present invention is that it allows the "music minus one" concept to be expanded and perfected. For example, several digital audio tracks, each devoted to a particular instrument or group of instruments, can be digitally subtracted from a track representing a full orchestral mix. Not only does this allow unheard of flexibility, but the digital subtraction (phase inversion) allows near perfect results when compared with analog techniques. (Instead of the phase inversion being accomplished in subtraction hardware, specific tracks could be recorded 180 degrees out of phase compared with the full mix recording so that track addition effects signal deletion.)
It is an object of this invention to provide a system and method for a software (e.g., music) publisher to record on a software carrier, such as an optical disk, numerous audio tracks in a way which allows them, during play, to be processed and combined in accordance with menu choices made by the user. In a sense, the invention constitutes a new form of consumer entertainment.